Laminated photocatalytic pulp paper and process for producing the same as well as splitting and disaggregating apparatus using for the process, paper string comprising the laminated photocatalytic pulp paper and process for producing the same and molded article comprising the paper string

ABSTRACT

An object of the present invention is to provide a laminated photocatalytic pulp paper having a variety of uses such as a filter material, a packaging material, a construction material and the like, which has the antibacterial property, the bad smell degrading property and handful substance oxidatively degrading property, is useful for use in air treatment, water treatment and soil treatment and, at the same time, can improve the photocatalytic activity effect itself of titanium oxide. According to the present invention, there is provided a laminated photocatalytic pulp paper characterized in that a wastepaper pulp is laminated on a photocatalytic pulp composition in which 40-95 wt % of a pulp and/or a paper having the water content of 3 wt % or less, an average fiber diameter of 5-300 μm and an average fiber length of 0.1-70 mm are blended with 5-60 wt % of titanium oxide, and a paper string comprising this pulp paper.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a laminated photocatalytic pulppaper, a molding material of which is mainly a pulp and/or a paper and awastepaper, preferably a wastepaper of newspaper, and which has thephotocatalytic activity and a process for producing the same and, moreparticularly in considering recycling of wastepapers of newspapers, itprovides a laminated photocatalytic pulp paper which can be widelyapplied to various uses as a furniture, a building material and ageneral packaging material such as a filter material, a paper slidingscreen, a paper for a sliding screen, a wall paper, a blind, a panel, alamp shade, a bed sheet, a curtain, a carpet, a sofa and a sheet, and aflexible composite packaging material, as well as a particular packagingmaterial for, example, antimold use, an interior material for a car, afacing material of an electric product for house use, and a raw materialfor and an article of various molded articles such as daily necessaries,and a film, a sheet, an adhesive or an adhesive resin layer, variouscoating agents or a coating resin membrane, or a paint or a paint resinmembrane, which has the deodorizing and the antibacterial properties andwhich can improve or effectively exert the photocatalytic properties oftitanium oxide, that is, the properties of titanium oxide of beingactivated by an ultraviolet ray and oxidatively degrading organicmaterials, ammonia, NOx, SOx and the like such as the deodorizing andthe antibacterial properties, by adsorbing titanium oxide onto a pulpand/or a paper, preferably laminating a wastepaper of newspaper whichwent through a DIP step, for example, in a paper making step, orlaminating wastepapers obtained by separately drying wastepapers ofnewspapers via an adhesive.

[0003] The present invention also relates to the novel use developmentof the aforementioned laminated photocatalytic pulp paper and provides apaper string comprising the laminated photocatalytic pulp paper as apackaging material as well as other daily necessaries including a mat, acage, a reed screen, a shop curtain and a cap, and a clothing, whichhave the deodorizing property and the antibacterial property, or as awater-soluble pet sand which can be flushed down in a washing toilet andhas the antibacterial function and the deodorizing function for moreeffectively treating bad smell produced from feces and urine of a pet,and other various molded articles or materials, and a molded articlecomprising the paper string.

[0004] 2. Description of the Prior Art

[0005] The above kind of titanium oxide has been hitherto used as adeodorizing filter or provided as a coating agent, and used in order toobtain the stainproofing or the antibacterial properties of the surfacesby forming a film by coating on an objective material and drying it. Inaddition, there has been no conventional techniques for a paper stringhaving photocatalytic properties.

[0006] However, these previous articles lead to the disadvantageousresults that the reacting rate is slow or the completion of the reactionis remarkably late, in the case of articles obtained by coating titaniumoxide or inserting and fixing titanium oxide into gaps between fibers.

[0007] A main object of the present invention is to provide a laminatedphotocatalytic pulp paper having the antibacterial, antimold,stainproofing and bad smell degrading, deodorizing and harmful materialoxidatively degrading effects, and which is widely used for a packagingmaterial, a building material, a filtering material and the like, and aprocess and for producing the same.

[0008] The present invention also provides a paper string and a moldedarticle as a packaging material suitable for the aforementioned varioususes, or as a material for various molded articles, which retain thephysical properties as a packaging material such as the tensilestrength.

SUMMARY OF THE INVENTION

[0009] In order to attain the aforementioned objects, a laminatedphotocatalytic pulp paper of the present invention is characterized inthat a virgin pulp or a wastepaper pulp is laminated on a photocatalyticpulp composition as a blend in which 40-95 wt % of a pulp and/or a paperhaving the water content of 3 wt % or less, an average fiber diameter of5-300 μm and an average fiber length of 0.1-70 mm are blended with 5-60wt % of titanium oxide.

[0010] In addition, a thermoplastic resin can be blended with thetitanium oxide, the pulp and/or the paper at an amount of 25-100 wt %relative to a total weight of the titanium oxide, the pulp and/or thepaper, and a virgin pulp or a wastepaper pulp can be laminated on theblend.

[0011] A process for producing the laminated photocatalytic pulp papercomprises a step of imparting the stirring impact force to a blendobtained by blending 40-95 wt % of a pulp and/or a paper which has beensplit and disaggregated to an average fiber diameter of 5-300 μm and anaverage fiber length of 0.1-70 mm with 5-60 wt % of titanium oxide tostir and, whereby, the shear exothermic heat is generated by a shearingforce based on the stirring impact force and the blend is dried by thisshear exothermic heat to reduce the water content to 3 wt % or less, astep of swelling the pulp and/or the paper upon the drying to obtain athree-dimensionally entangled material, a treatment step of pushing thetitanium oxide against the fiber surface of the pulp and/or the paper bythe stirring impact force to fix thereto, and a step of laminating avirgin pulp or a wastepaper pulp in a paper making step after thetreatment step of pushing and fixing the titanium oxide.

[0012] In addition, in the above process, a thermoplastic resin can beblended with the titanium oxide, the pulp and/or the paper at an amountof 25-100 wt % relative to a total weight of the titanium oxide, thepulp and/or the paper.

[0013] When the wastepaper pulp comprises a newspaper wastepaper via aDIP step, it is suitable for reusing a newspaper wastepaper andlamination can be performed using this wastepaper pulp as a corematerial or a substrate.

[0014] Furthermore, a synthetic fiber having the average fiber length of1 to 100 mm, the average diameter of 10 to 40 μm and a melting point of120° C. or higher can be blended into 5 to 60 wt % of titanium oxide and40 to 95 wt % of a pulp and/or a paper at a maximum ratio of 1:9.

[0015] In the case where the raw pulp as a photocatalytic pulpcomposition is a paperboard-like dry pulp, the process includes asplitting or disaggregating step 303 by which the above dry pulp istreated, that is, the dry pulp is cut into a plurality of sections to betreated, and the impact grinding force is applied to the formedindividual sections to obtain pulp fibers which are ground andaggregated into cotton-like fibrous pulp fibers, have approximately thesame length of a fiber like raw pulp and have no fiber hair even withthe grinding.

[0016] In addition, an apparatus for splitting or disaggregating the drypulp is for treating a plate-like dry pulp, and is provided with a fixedside impact grinding means in which a port 132 for supplying a pluralityof chopped small sections to be treated is past in the center of a fixeddisc 131 and respective fixing pins 134 are successively provided on aplurality of rotating loci, a mobile side impact grinding means in whicha mobile disc 141 is rotatably and drivably provided opposite to thefixed circular disc 131 and a plurality of mobile pins 144 differentfrom the respective fixing pins 134 are successively provided on aplurality of rotating loci on the mobile disc 141, and preferably arecovery means for discharging contaminants which is opened in adischarge outlet via a screen 151 positioned on a combinatorialcircumference of the respective fixing pins 134 and the respectivemobile pins 144 and provided with small pores having the predetermineddiameter, and further a take-out means for taking out small sections tobe treated which remain in the screen 151 and which have been ground andaggregated into cotton-like fibrous pulp fibers 84, through an outlet.

[0017] The thus recovered pulp fibers 84 are transferred to a next step,that is, a step of fixation-treating titanium oxide.

[0018] Furthermore, a paper string comprising the laminatedphotocatalytic pulp paper of the present invention is characterized inthat the laminated photocatalytic pulp paper which have been cut into anarbitrary width of 5-50 mm are twisted at a basis weight of preferablyabout 20-80 g/m². This can be cut into a diameter of about 2-5 mm and alength of about 5-30 mm and can be used as a water-soluble pet sandwhich has the antibacterial property and the deodorizing property formore effectively treating bad smell produced from pet feces and urine astreatment of pet feces and urine, in addition to the utility as apackaging material and the like.

[0019] The process for production comprises cutting the laminatedphotocatalytic pulp paper into a width of 5-50 mm, which is wound in aroll-manner and, thereafter, twisted for example at around 15-30 turns.

[0020] In addition, a step of stacking a plurality of, for example,10-40 of the paper strings on the same plane and immersing it in awater-soluble adhesive to dry can be repeated about three times and theadhesive can be removed by sanding to obtain a molded belt-like flatstring.

[0021] In addition, a woven fabric can be manufactured using the paperstring as a weft and a thread comprising a natural fiber such as acotton yarn or a chemical fiber such as rayon as a warp and, further,the paper string, the flat string and the woven fabric may be combinedto use for a variety of utilities.

BRIEF DESCRIPTION OF DRAWINGS

[0022] The objects and advantages of the invention will become apparentfrom the following detailed description of preferred embodiments thereofprovided in connection with the accompanying drawings throughout whichlike numerals denote like elements and in which:

[0023]FIG. 1 is a view showing the surface of the photocatalytic pulpcomposition of an embodiment of the present invention measured by ascanning microscope. (A) magnification 200 and (B) magnification 750;

[0024]FIG. 2 is a view showing the surface and the cross section of thephotocatalytic pulp composition of an embodiment of the presentinvention measured by a scanning microscope. (A) indicates the surface,magnification 750;

[0025]FIG. 3 is a partial cross sectional view schematically showing theoutlined construction of an impact grinding apparatus used in a step forsplitting and disaggregating the present paperboard like dry pulp;

[0026]FIG. 4 is a plane view of FIG. 3;

[0027]FIG. 5 is a schematical front view for explaining the impactgrinding action in the splitting and disaggregating step of FIG. 3; and,

[0028]FIG. 6 is an outlined view showing an use example of the impactgrinding means used in the splitting and disaggregating step of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Example (1): Materialto be Laminated for a Photocatalytic Pulp Composition

[0029] In this Example, a pulp and/or a paper used as a raw materialincludes not only a so called virgin pulp in a paper making step butalso a wastepaper pulp or a pulp obtained by mixing the both at 1:1, andthe paper includes a normal paper and widely a wastepaper such aswastepaper of newspaper.

[0030] A wastepaper which is ground with a cutter mill having 10 mm 10mm screen and, thereafter, treated and which contains a large amount ofa printing ink is preferably bleached or colored with a DIP treatment ina paper making step like a wastepaper to be laminated as describedbelow.

[0031] And the average fiber diameter is 5 to 300 μm and the averagefiber length is 0.1 to 70 mm, and the bulk specific gravity is 0.005 to0.04 in the case of the paper fiber and 0.24 in the case of the virginpulp and/or paper. 80 wt % of it (upon this, the pulp and/or papercontains about 8 wt % of water) and 20 wt % of titanium oxide areincorporated.

[0032] The average fiber diameter of the pulp and/or the paper of 5 to300 μm, and the average fiber length of 0.1 to 70 mm means a particlesize of 50% by weight in accumulative weight percent of the pulp and/orthe paper.

[0033] In the case of a paper, a paper is grinding treated with acrusher and past through a screen having 10 mm mesh, which is used.

[0034] In addition, a printing ink in a wastepaper has no problem upontreatment except that a product is slightly colored.

[0035] In the case of paperboard like dry pulp, the dry pulp is cut intoa plurality of sections, and the impact grinding force is applied to theformed individual sections to obtain pulp fibers which are ground andaggregated into cotton-like fibrous pulp fibers, have approximately thesame length of that of a fibrous raw pulp and have no fiber hair evenwith the grinding. Such the paperboard like dry pulp after the splittingand disaggregating step 303 is used.

[0036] An impact grinding means used in this step is referred to as“separator” for convenience in this Example.

[0037] In FIGS. 3 to 6, a separator 130 is past and opened in a port 132for supplying respective small sections to be treated in the center of afixed circular disc 131, a fixed end plate 133 is opposite to the fixedcircular disc 131 separating by a treating space 155, respectivecircumferential edges of the fixed end plate 133 are fixed to the fixedcircular disc 131 with a circumferential side plate 135. A mobilecircular disc 141 which is rotated and driven by a rotating transverseaxis 142 in the interior of the treating space 155, the rotatingtransverse axis is supported pivotally by each bearing 143, 143. Therotating transverse axis 142 is rotated and driven by a rotating drivingmeans such as a motor and the like. And, on the fixed circular disc 131,a plurality (6 in this Example) of respective pins 134 are provided onrotating loci a1 to a6 (relative to a mobile plate 141) (FIG. 5) on aconcentric circle, and 16 24 32 36 40 42 of respective fixing pins 134are successively provided from the center of the fixed circular disc 131on a concentric circle towards the circumferential edge in this Example.On the other hand, on the mobile circular disc 141, a plurality (6 inthis Example) of mobile pins 144 which are different from the respectivefixing pins 134 and positioned alternately on rotating loci b1 to b6 aresuccessively (4 4 4 4 4 6) provided on the concentric circle from thecenter of the mobile circular disc 141 towards the circumferential edge,and which are positioned so that the splitting and disaggregating actionis obtained between respective fixed and mobile pins 134, 144 by theimpact grinding force.

[0038] Further, a screen 151 having the predetermined mesh in whichsmall pores having the desired diameter are formed by punching iscircumferentially provided on the circumferential side of a mobilecircular disc 141 between the circumferential side plate 135 separatingby a discharge port 156, and a discharge port 152 is provided below adischarge space 156. A blower 157 is communicated with the dischargeport 152 in a separator 130 as shown in FIG. 6.

[0039] And, a discharge port 152 is communicated with a recovery tank250 via a discharge tube 239 provided with a blower 157.

[0040] In addition, as the screen 151, a screen having the diameter ofabout 0.8 mm to 2.0 mm, though depending upon the rotation number of amobile pin described below is used. Further, a take out port 153 isformed on an lower part in the interior of a screen 151 of a treatingspace 155 (FIG. 3). The grinding force which is applied to smallsections to be treated is weakened by increasing the clearance betweenthe respective fixed and mobile pins 134, 144 and the grinding force isstrengthened by decreasing the clearance. A blower 157 which sucks airin a separator 130 is communicated with the take out port 153 as shownin FIG. 6, and may be communicated with a supply port 132 via thisblower 157.

[0041] In addition, as shown in FIGS. 3 and 6, the followingconstruction may be taken: A take out port 153 and a treating space 155are communicated via a communicating tube 235, the compressed air whichis circulated in a treating space 155 from a take out port 153 and whichis from a compressed air supplying source (not shown) is introduced in acommunicating tube 235 via a piping 236, and ground pulp fibers andalien substances which are discharged from a take out port 153 arecirculated again in a treating space 155 in a separator 130.

[0042] Alternatively, a ramificating tube 237 communicating with a tank240 for recovering the pulp fibers, or the pulp fibers and aliensubstances is provided by branching a supply port side of thecommunication tube 235, a two directional valve 238 which can beappropriately switched every set time, for example, with a timer circuitis provided at a ramificating point of this ramificating tube 237, thedownstream side of the communicating tube 235 is closed with a magneticvalve and the ramificating tube 237 side is opened, the pulp fiberswhich remain in a screen 151 are sucked and recovered in a recovery tank240 via a ramificating tube 237. Alternatively, a magnetic valve whichopens and closes the ramificating tube 237 and a magnetic valve whichopens and closes the downstream side of the ramificating tube 235 areprovided, and these two magnetic valves may be opened and closedalternately (FIG. 6).

[0043] By rotating a rotating transverse axis 142 with a rotatingdriving means such as a motor or the like to rotate a mobile circulardisc 141 and supplying respective small sections to be treated in asupply port 132, the respective small sections to be treated areloosened into smaller fibers between respective fixed and mobile pins134, 144 by the impact grinding force in the center of the treatingspace 155 and, on the other hand, the diameter of the alien substancesbecomes about 2 to 6 mm in an indefinite manner by the impact grindingforce. That is respective small sections to be treated are beaten andground or pulverized into small pieces with the impact by respectivefixed and mobile pins 133 and 144, and since the bending action isrepeatedly applied to the respective small sections to be treated, thefinely divided paperboard is separated from small sections to betreated. Like this, the pulp fibers and alien substances whichconstitute the small sections to be treated are separated every itskind, respectively, the boardpaper is loosened into fibers and the aliensubstances are ground into fine pieces, respectively.

[0044] During this period, by an air stream produced by the compressedair which is supplied in a treating space 155 by the centrifugal forceby rotation of a mobile circular disc 141 or the suction force of ablower 157 or via a piping 236, the separated and fiberized paper layerand pulp fibers or fiberized paper layer and a small amount of aliensubstances gradually approach the circumferential side of acircumferentially provided separator 130 of a screen 151 in the mixedstate. Thereafter, the fiberized pulp is past through a screen 151 whichis formed into meshes having the diameter of about 0.8 to 2 mm anddischarged into a discharge space 156 and, thereafter, sucked towardsthe outside via a discharge port 152 and a blower 157, and recovered ina recovery tank 250 via a discharge tube 239. On the other hand, thethin substance pieces and a small amount of pulp fibers which areaggregated into a cotton-like fibrous pulp fibers can not pass a screen151 and remain in the treating space. When the recovery of the pulpfibers is completed, the alien substances which remain in the interiorof a treating space 155 are discharged outwards from a take out port153.

[0045] The discharged substances are recovered into a recovery tank 240via a ramificating tube 237 by closing the downstream side of thecommunicating tube 235 and opening the ramificating tube 237 side with atwo directional magnetic valve 238 of a ramificating tube 237 which isbranched on the supply port side of the communicating tube 23 and whichis communicated with a tank 240 for recovering the pulp fibers to suckthe alien substances which remain in a screen 151.

[0046] In FIG. 3, the connection of a communication tube 235 to aramificating tube 237 is carried out via a flange 154 provided on apiping in which the upstream side and the take out 153 side of acommunication tube 235 are branched (towards a rear of a paper plane inFIG. 3).

[0047] The pulp fibers thus recovered are transferred to a next step.

[0048] Titanium oxide is effective when its particle size is smallerand, for example, the X ray diameter of 7 to 50 nm can be used.

[0049] The pulp and/or the paper and titanium oxide, or these materialstogether with synthetic fibers are placed, and the water content oftitanium oxide and the pulp and/or the paper is adjusted to 3 wt %,preferably to 1 wt % or less by producing the shearing heat release bythe shearing force based on the stirring impact force by a stirringimpact blade rotating at a high speed in a mixer to raise a temperatureto about 120° C. In this step, water is evaporated from the pulp and/orthe paper to dry it and at the same time the pulp and/or the paper inthe case of a paper undergo the grinding action by the impact force, isswelled at the same time with the drying, the fibers become hairy andaggregated into cotton-like fibrous pulp fibers to obtain threedimensionally entangled fibers. Thereafter, titanium oxide is attachedto or inserted in to fix the fiber surface and the interior of thefibers by the stirring impact force by the stirring impact blade or theexternal pressing force accompanied with the shearing force.

[0050] The synthetic fiber is preferable when the average fiber lengthis 1 to 100 mm, the average diameter is 10 to 40 μm, and a melting pointis 120° C. or higher.

[0051] A virgin pulp has usually the water content of around 10 wt % inthe case of a plate-like dry pulp but, also in the case of the higherwater content, a virgin pulp is to be pre-dried or is preferablypre-dried to the water content of 10 wt % or less with the mixer or theknown drier before mixing of titanium oxide.

[0052] In this step, the attachment and fixation of titanium oxide arecompleted to form “photocatalytic pulp composition”.

[0053] In this step, the pulp and/or the paper in the raw material dosenot become a large lump, are aggregated while cotton-like fibrous pulpfibers without the mutual firm entanglement of the individual fibersand, in this sense, the three dimensionally entangled fibers are formedand the individual pulp and/or paper are formed in such the form thattitanium oxide is attached to all the surface of the fiber of the pulpand/or the paper. Since these individual are aggregated into cotton-likefibrous pulp fibers from a paper, there is no adhesive propertiesbetween the simple pulp and/or the paper and the lump itself has thehigh bulk sepcific gravity. Therefore, the photocatalytic pulpcomposition formed by this step is a better material as a photocatalyticpulp composition which can be made into a paper in various known papermaking steps.

[0054] The above step is described in more detail. Since the watercontent of the pulp and/or the paper is 3 wt % or less, the interfacebetween titanium oxide and the pulp and/or the paper is lost, titaniumoxide is dispersed into the pulp and/or the paper at a uniform density,titanium oxide becomes easy to be absorbed onto or attach to the pulpand/or the paper and at the same time the pulp and/or the paper is mixedand dispersed while completely surrounding the circumference of the pulpand/or the paper.

[0055] As such, the present photocatalytic pulp composition can be usedas a raw material to form a paper by various paper making methods.

[0056] In addition, a plastic fiber or glue, starch, wax or a resinadhesive such as vinyl acetate and acryl system can be mixed therein ina paper making step to prepare a molded photocatalytic pulp composition.

[0057] A photocatalytic pulp paper was prepared using the above pulpcomposition having the photocatalytic activity.

[0058] As Examples and Comparative Examples of a photocatalytic pulpcomposition using a photocatalytic pulp composition, titanium oxide ST01 (manufactured by Ishiharatechno Company) having the X ray diameter of7 nm, the titanium oxide content of 90 wt % or more and the specificarea of 300 m²/g was used to treat with the stirring impact force by astirring impact blade rotating at a high speed in the mixer (120° C.).

[0059] Photocatalytic Pulp Composition: Example 1

[0060] About 2.5 kg of a plate-like dry pulp is treated in the splittingand disaggregating step to obtain about 2.0 kg of aggregated cotton-likefibrous pulp (the water content; 0.5 wt %).

[0061] Photocatalytic Pulp Composition 2; Example 2 (FIG. 1 and FIG. 2)

[0062] Crushed Paper fiber 2 kg (80 wt %), the water content 10 wt %;Treated in the splitting and disaggregating step.

[0063] Titanium oxide; 0.5 kg (20 wt %)

[0064] This was treated via a fixation treating step to obtain about 2.3kg of a photocatalytic pulp composition (The water content aftertreatment; 0.6 wt %).

[0065] Photocatalytic Composition Paper: Example 1

[0066] Using the photocatalytic pulp composition obtained in the above[Photocatalytic pulp composition 1: Example 1], the composition wasdiluted to the pulp concentration of 8 wt % to perform the beatingtreatment with a beater for 1 hour.

[0067] On the other hand, a beaten pulp raw material such as a virginpulp including a Japanese paper, herein for example, a wastepaper pulpcomprising a wastepaper of newspaper after a DIP step (de-inkingtreatment) was diluted with water to the pulp concentration of 8 wt %,beat treated for 1 hours, then a wet sheet of a pulp comprising aphotocatalytic pulp and a wastepaper of newspaper is made into a paperusing a paper making machine in the known paper making step. Aphotocatalytic pulp (50 g/m²) and a pulp comprising a wastepaper ofnewspaper (10 g/m²) after beating treatment were made into a paper usinga wire paper machine and a cylinder paper machine, respectively, whichwere overlapped, transferred to a press part and further dried to make apaper.

[0068] By the foregoing, a transparent, air-permeable white substratelayer was laminated on a photocatalytic pulp layer (Example 1).

[0069] Photocatalytic Pulp Composition Paper: Example 2

[0070] The photocatalytic pulp composition obtained in [Photocatalyticpulp composition 2: Example 2] and a wastepaper of newspaper were madeinto a paper as in Example 1.

[0071] Beater treatment time 1 hour

[0072] Concentration of photocatalytic pulp 8 wt %

[0073] Concentration of a wastepaper of newspaper pulp 8 wt %

[0074] Basis weight Total 60 g/m²

[0075] Photocatalytic pulp layer 50 g/m²

[0076] Newspaper wastepaper pulp layer 10 g/m²

[0077] [Photocatalytic Pulp+Paper; Comparative Example 1]

[0078] Paper fibers; 2 kg (80 wt %) and titanium oxide; 0.5 kg (20 wt %)were diluted to the pulp concentration of 8 wt % with a beater withoutusing a mixer in the above embodiment and Example, to make a paper.Basis weight Total 50 g/m²

[0079] The test results of the above Examples 1 and 2 and ComparativeExample 1 are shown below.

[0080] Test Conditions

[0081] Concentration of added acetaldehyde about 820 ppm

[0082] Light intensity about 1 mW/cm²

[0083] Reaction vessel 1 liter

[0084] Photocatalytic Pulp Paper and Other Comparative Example

[0085] Sample size 8×8 cm Basis weight: Examples 1, 2 Total 60 g/m²

[0086] Comparative Example 1 50 g/m² TABLE 1 Photocatalyst Co₂ Co₂initial production Co₂ production Acetaldehyde producing rate rateinitial at 1 h at 2 h speed vanishing speed ppm/min (%) (%) (ppm/min)Test Ex. 1 29.8 79 100 18.9 Test Ex. 2 24.0 68 100 17.5 Comp. Ex. 1 11.038 47 7.4

[0087] The photocatalytic Co₂ initial producing rate is obtained by thefollowing formula;

(Apparent Co₂ initial producing rate)−(light control Co producing rate)

[0088] Acetaldehyde initial vanishing rate is the vanishing rate at 30min. after photo-irradiating.

[0089] The production rate (%) at 1 h or 2 h is a ratio of theproduction relative to theoretical value and was calculated by onlyphotocatalyst portion.

[0090] The initial acetaldehyde vanishing rate (%) is concentration at 1h/initial concentration 100.

[0091] The photocatalyst+pulp paper; a paper of Comparative Example 1has the extremely low photocatalytic activity and the acetaldehydevanishing rate is slow.

[0092] To the contrary, the photocatalytic pulp composition Test Example1 shows 100% of Co₂ production rate at 2 h like Test Example 2, and itcan be seen that after the concentration of acetaldehyde is decreased,the sufficient reaction occurs.

[0093] It was seen that simple mixing of titanium oxide can not affordthe effects and the present invention extremely can improve thephotocatalytic activity.

[0094] FIGS. 1(A) and (B) and FIG. 2 show scanning microscopicphotographs of the photocatalytic pulp composition and photocatalyticpulp composition (Example 2) of Example 2, respectively, it can be seenthat titanium oxide is attached and connected to the external face of apulp raw material and the state where titanium oxide is attached ismaintained on the external face of a pulp and also in the interior of apaper even according to a paper making method using water. This is alsoclear from the fact that little titanium oxide is dissolved in waterwhich was added at a point of stirring in a paper making experiment ofTest Example.

[0095] [Photocatalytic Pulp Composition: Example (3), PhotocatalyticPulp Paper: Example (3)]

[0096] In this Example, a ratio of blending titanium oxide, a pulpand/or a paper which forms a photocatalytic pulp composition are thesame as those of the above Example (1) for preparation.

[0097] In addition, the same titanium oxide, the pulp and/or the paperas those of Preparation Example (1) can be used as a raw material.

[0098] In this Example, as in the Preparation Example (1), titaniumoxide and a pulp and/or a paper are blended and at the same time 25 to100 wt % of a thermoplastic resin is added to the total weight of thetitanium oxide and pulp and/or paper to form a photocatalytic pulpcomposition (Photocatalytic pulp composition: Example (3)).

[0099] The photocatalytic pulp composition is formed, and a recycledpaper comprising a wastepaper pulp obtained by DIP treating a wastepaperof newspaper can be laminated on the composition (Photocatalytic pulppaper: Example (3)).

[0100] As this thermoplastic resin, various resins can be used. Inaddition, a thermoplastic resin in the powder, particle and sheet formscan be used. Preferably, a thermoplastic resin having a particle size of1 mm or less in the case of a powdery or particulate thermoplastic resin, or a thermoplastic resin having the thickness of 1 mm or less in thecase of a sheet like thermoplastic resin is ground into pieces havingthe side of 10 mm or less to use it.

[0101] When the produced photocatalytic composition is heated to form amolded photocatalytic pulp, if heated at a high temperature, a pulp inthis photocatalytic pulp composition is burnt by this heat in some casesand, therefore, it is preferable that a thermoplastic resin having alower melting point such as PE (LLD; linear low density) and vinylacetate is used as compared with a thermoplastic resin having arelatively high melting point such as polyester, polycarbon and thelike.

[0102] A pulp and/or a paper and a thermoplastic resin which constitutethe photocatalytic pulp are not required to place in a mixer as aseparate raw material and, for example, a composite film having a paperlayer laminated with a thermoplastic resin film and which is used for amilk pack is ground into small pieces having the side of around 10 mmand, thereafter, the pieces may be placed in the mixer as describedabove.

[0103] In this case, a paper layer of the composite film becomes a pulpfiber which constitutes a photocatalytic pulp composition and athermoplastic resin layer becomes a thermoplastic resin whichconstitutes the formed photocatalytic pulp composition to be formed.Therefore, an amount of titanium oxide to be blended is determinedtaking a ratio of a pulp component relative to a thermoplastic resincomponent contained in a composite film into consideration and at thesame time, as necessary, a thermoplastic-resin and/or a pulp and/or apaper are added so as to adjust a ratio of respective raw materials tothe aforementioned ratio.

[0104] After the pulp and/or the paper and titanium oxide and thethermoplastic resin are placed in a mixer, the mixer is actuated toproduce the shearing heat by the shearing force based on the stirringimpact force by a stirring impact blade which rotates at a high speed inthe mixer and a temperature is raised to about 120° C. to adjust thewater content of the pulp and/or the paper to 3 wt %, preferably 1 wt %or less. In this step, water is evaporated from the pulp and/or thepaper to dry it and, at the same time, the pulp and/or the paper in thecase of a paper undergoes the grinding action by the impact force tobecome fibrous and, further, which is swelled accompanied with thedrying, fibers are scuffed up and aggregated into a cotton-like fibrousto form three dimensionally entangled fibers. Thereafter, titanium oxideis attached to or inserted into to fix the surface of the fibers or alsothe interior of the fibers by the external pressing force accompaniedwith the stirring impact force or the shearing force by the stirringimpact blade.

[0105] In addition, at the same time, at least a part of a thermoplasticresin placed into a mixer also undergoes the grinding action, and areground into small pieces which are attached to or inserted into to fixthe surface of the fibers and the interior of the fibers by the pushingforce accompanied with the stirring impact force or the shearing forceby the stirring impact blade like the aforementioned titanium oxide.

[0106] When a composite film such as a milk pack is used as theaforementioned pulp and/or the paper and thermoplastic resin, smallsections of the composite film placed into a mixer are separated into athermoplastic resin layer and a paper layer by the stirring impact forceby the shearing impact blade and the separated paper layer is ground bythe stirring impact force and aggregated into cotton-like fibrous pulpfibers as described above for the paper.

[0107] In addition, at least a part of a thermoplastic resin layer isalso ground into small pieces by the stirring impact force and attachedto or inserted into to fix the surface of the pulp fibers and theinterior of the pulp fibers like the aforementioned separately placedthermoplastic resin.

[0108] In addition, a thermoplastic resin is not required to melt by theheat upon stirring with a mixer as long as it is attached to or insertedinto to fix the pulp fibers.

[0109] The present photocatalytic pulp composition can be easily formedinto a molded photocatalytic pulp such as a press sheet and the like,for example, by pressing under heating. In addition, since the moldedarticle which was formed by the method binds firmly between pulp fibersbecause a thermoplastic resin attached to or inserted in to fix thesurface or the interior of the pulp fibers serves as a binder, itbecomes a molded article such as a tough press sheet and the like.

[0110] A pulp composition having the photocatalytic activity obtained bythe aforementioned Preparation Example was used to manufacture a molded,photocatalytic pulp composition (press sheet).

[0111] Example and Comparative Example of a Photocatalytic Pulp PaperUsing a Photocatalytic Pulp Composition

[0112] As an Example, a thermoplastic resin PE [Urdozex 4030P (powder):Mitsui Petroleum chemichal Industries Co., Ltd.] was used and the otherraw materials are the same as those of the aforementioned Example 2 andthe molded press sheet and a wastepaper pulp comprising a wastepaper ofnewspaper after a DIP step (deinking treatment) were made into a paperto dry and laminated on one side via an adhesive with hot press.

[0113] Photocatalytic Pulp Paper; Example 3

[0114] Paper fiber; 2 kg (80 wt %), the water content 10 wt %

[0115] Titanium oxide; 0.5 kg (20 wt %)

[0116] Thermoplastic resin: PE 1.5 kg (Paper fiber+60 wt % relative tothe total weight of titanium oxide)

[0117] The water content after treatment: 0.5 wt %

[0118] The above raw material is placed into a mixer and stirred, and atemperature is raised to about 120° C. to adjust the water content ofthe paper fiber to 3 wt %, preferably 1 wt % or less.

[0119] 0.51 g of the photocatalytic pulp composition obtained asdescribed above was spread 8×8 cm, nipped with a Teflon sheet, andheated in a thermostatic chamber at 150° C. for 2 hours while applying aload of 1 kg to form a molded photocatalytic pulp (press sheet) havingthe basis weight of 50 g/m², the molded press sheet and a wastepaperpulp comprising a wastepaper of newspaper after a DIP step (deinkingtreatment) were made into a paper to dry. The basis weight 10 g/m² waslaminated on one side via an adhesive with hot press which was used as asample (Example 3).

[0120] Beater treatment time 1 hour

[0121] Concentration of photocatalytic pulp 8 wt %

[0122] A photocatalytic pulp was not treated with a beater.

[0123]

[0124] Basis weight Total 60 g/m²

[0125] Photocatalytic pulp layer 50 g/m²

[0126] Newspaper wastepaper pulp layer 10 g/m²

[0127] Comparative Example 2 (The Aforementioned Photocatalytic PulpPaper; Example 2)

[0128] Crushed Paper fiber; 2 kg (80 wt %), the water content 10 wt %

[0129] Titanium oxide; 0.5 kg (20 wt %)

[0130] The water content after treatment; 0.6 wt %

[0131] The photocatalytic pulp composition obtained in theaforementioned Example (2) was used and made into a paper according tothe same step of the Comparative Example 1 (basis weight, total 50g/m²), a wastepaper pulp comprising a wastepaper of newspaper after aDIP step (deinking step) and this molded photocatalytic pulp were madeinto a paper to dry (basis weight, total 10 g/m²), which was laminatedone side via an adhesive with a hot press.

[0132] Beater treatment time 1 hour

[0133] Concentration of photocatalytic pulp 8 wt %

[0134] Concentration of wastepaper of newspaper 8 wt %

[0135] Basis weight Total 60 g/m²

[0136] Photocatalytic pulp layer 50 g/m²

[0137] Newspaper wastepaper pulp layer 10 g/m²

[0138] The results comparing the molded photocatalytic pulp of theaforementioned Example 3 and Comparative Example 2 under the followingconditions are shown in Table 2.

[0139] Experimental Conditions

[0140] Concentration of added acetaldehyde about 820 ppm

[0141] Light intensity about 1 mmW/cm²

[0142] Reaction vessel 1 liter

[0143] Photocatalytic pulp paper and other Comparative Example

[0144] Sample size: 8×8 cm Basis weight Total 60 g/m² TABLE 2Photocatalyst Co₂ Co₂ Acetaldehyde Co₂ Co₂ initial production productioninitial 100% producing rate rate vanishing production rate at 1 h at 2 hrate time ppm/min (%) (%) (ppm/min.) time (h) Test 24.3 70 100 16.2 2Ex. 3 Com. 24.0 68 100 17.5 2 Ex. 2

[0145] It was confirmed that the molded photocatalytic pulp (presssheet+wastepaper; Example 3) formed from the photocatalytic pulpcomposition manufactured in Example 3 has approximately the sameproperties as those of the photocatalytic pulp paper (ComparativeExample 2)

[0146] Therefore, it was revealed that the molded photocatalytic pulp ofthe aforementioned Example 3 has the effect of improving thephotocatalytic activity efficiency which can not be obtained by simplymixing titanium oxide.

[0147] In addition, since CO₂ production rate at 2 hours is 100%, thesufficient reaction occurs even after the concentration of acetaldehydeis decreased.

[0148] The aforementioned regenerated paper, having the photocatalyticactivity function, in which waste papers are laminated, can be laminatedinto a two-layered or a three-layered laminate with a normal paper, asynthetic paper, a plastic film or a non-woven fabric by using as alaminating material such as a wastepaper pulp core material, a substrateor the like, with a paper on the photocatalytic side as an inner, outeror intermediate layer. In this case, by using a material having theexcellent light transmissibility such as a normal paper, a syntheticpaper, a non-woven fabric, a woven fabric, a non-woven fabric having thelow fiber density, a woven fabric having the crude weave pattern, atransparent film and the like having the light transmissibility orhaving many openings as a core material or a substrate, in the casewhere a photocatalytic pulp is positioned on the light source side andis arranged so as to be exposed directly, as well as also in the casewhere the photocatalytic pulp is not positioned on the light source sidesuch as in the case where the photocatalytic pulp is held between corematerials or substrates and the like, the photocatalytic pulp isirradiated with the light having passed through a core material or asubstrate and, whereby, the photocatalytic property of titanium oxide issuitably exerted and, at the same time, by providing a core material ora substrate with openings or the like having the air permeability, themolded photocatalytic pulp becomes easy to use as a filter or the like.

[0149] [Example 1 of a Paper String as a Molded Article Comprising theLaminated Photocatalytic Pulp Paper]

[0150] A cow's milk pack was treated in the same splitting anddisaggregating step as that of Example 1 to obtain a pulp. To this wasfixed about 23 wt % of titanium oxide in the aforementionedfixing-treatment step to obtain a photocatalytic pulp composition.

[0151] Then, the resulting photocatalytic pulp composition was dilutedto the pulp concentration of 8 wt % and beat-treated with a beater for 1hour.

[0152] On the other hand, 43 g/m² of a pulp obtained by treating thesame cow's milk pack as described above was diluted with water to thepulp concentration of 8 wt %, beat-treated for 1 hour and, then, aphotocatalytic layer (20 g/m²) into which 15 wt % of a photocatalyticpulp had been blended and a pulp layer (43 g/m²) comprising a cow's milkpack were made into a paper with a wire paper machine or a cylinderpaper machine, respectively, using a paper machine for making a paper inthe known paper making step, and they were stacked, transferred to apress part, further dried and made into a paper to obtain 63 g/m² of atwo-layered photocatalytic pulp paper.

[0153] Experiment 1 in the following Table shows the evaluation ofphysical properties of the aforementioned photocatalytic pulp paper.

[0154] After a sample was allowed to stand in a chamber at a constanttemperature and a constant humidity for 24 hours, measurement wasperformed according to JIS P8124, JIS P8113 and JIS P8135.

[0155] This photocatalytic pulp paper was cut into a width of 48 mm witha slitter, and wound into an about 500 m roll, which was twisted by theknown ring twister so that the aforementioned photocatalytic pulp layerbecomes an outer surface to obtain an about 3 mm φ paper string.

[0156] Experiment 2 in the following Table shows the evaluation ofphysical properties of a paper string comprising the aforementionedphotocatalytic pulp paper.

[0157] After the paper string was subjected to moisture conditioning ata temperature of 20±5° C. and a relative humidity of 65±2% for 48 hoursor longer so that it dose not become dry, measurement was performedaccording to JIS Z1518-1976. TABLE 3 Experiments 1 and 2 Ex. 1 Ex. 2Experiment 1 Basis weight (g/m²) 63 38 Tensile strength(longitudinal)(Kg/15 mm) 4.2 3.8 Tensile strength (transverse)(Kg/15 mm)2.06 0.78 Wet tensile strength 1.6 0.38 (longitudinal)(Kg/15 mm) Wettensile strength 1.13 0.18 (transverse)(Kg/15 mm) Experiment 2 Width(mm) 48 20 Size (mm) 3 1 Weight (g/10 m) 30.2 7.6

[0158] [Example 2 of a Paper String Comprising the AforementionedLaminated Photocatalytic Pulp Paper]

[0159] According to the same manner as that of Example 1, there wasobtained 38 g/m² of two-layered photocatalytic pulp, which was made intoa paper, comprising a pulp layer (26 g/m²) obtained by treating aphotocatalytic layer (12/m²), to which about 15% of a photocatalyticpulp composition: titanium oxide 23 wt % fixation had been added, with acow's milk pack. Then, the two-layered photocatalytic pulp was twistedso that the aforementioned photocatalytic pulp layer became an outersurface, to obtain an about 1 mm φ paper string.

[0160] [Example 3 of a Long and Narrow String as a Molded ArticleComprising the Aforementioned Laminated Photocatalytic Pulp PaperString]

[0161] 16 paper strings prepared in Example 2 of a paper string werestacked on the same plane, and immersed in the varying concentrations(1st time: 30 wt %, 2nd time: 15 wt %: 3rd time: 3 wt % aqueoussolution) of water-soluble poly vinyl alcohol as a water-solubleadhesive and dried (immersion and drying were repeated three times) toobtain a long and narrow string having a width of 20 mm. Then, at leastone surface of the long and narrow string was subjected to sanding(manufactured by Amitecs; NS-15D; sandpaper #400) to expose aphotocatalytic layer.

[0162] Experiment 3 in the following Table 5 used, as a sample, thepaper strings of Examples 1 and 2, the long and narrow strings ofExample 3 before and after sanding, and a long and narrow stringcontaining no photocatalyst of Comparative Example 1.

[0163] Experimental Conditions

[0164] Gas/concentration: added acetaldehyde gas/20 ppm (concentrationafter absorbed onto a paper)

[0165] Irradiation intensity About 1 mW/cm²

[0166] Reaction vessel 3 liter

[0167] Sample: Cut to a total area of 5 cm 10 cm

[0168] Light source: 40 W Black light

[0169] Measurement: Measured with Gastec detecting tube 92L

[0170] Pretreatment: Dried for 1 day in a desiccator after irradiatedwith 1 mW/cm² ultra violet-ray for 15 hours. TABLE 4 Concentration ofacetaldehyde gas(ppm) Example 3 Example 3 Irradiation Before AfterComparative time Example 1 Example 2 sanding sanding Example 1  0 min 1818 19 18 19 20 min 6 4 16 5 18 60 min 0 0 15 0 17

[0171] A photocatalytic pulp paper including a wastepaper laminatedphotocatalytic recycling paper having the antibacterial, antimold,stainproofing and bad smell degrading, deodorizing and handful materialoxidatively degrading effects, and which is widely used for a packingmaterial, a building material, a filtering material and the like, apaper string comprising the laminated photocatalytic pulp paper and amolded article comprising the paper string which can quicken thereacting rate and the completion of the reaction remarkably and improvea photocatalytic property of titanium oxide can be provided.

[0172] Now, that the invention has been described. Thus, the broadestclaims that follow are not directed to a machine that is configure in aspecific way. Instead, said broadest claims are intended to protect theheart or essence of this breakthrough invention.

[0173] This invention is clearly new and useful. Moreover, it was notobvious to those of ordinary skill in the art at the time it was made,in view of the prior art when considered as a whole.

[0174] Moreover, in view of the revolutionary nature of this invention,it is clearly a pioneering invention. As such, the claims that followare entitled to very broad interpretation so as to protect the heart ofthis invention, as a matter of law.

[0175] It will thus be seen that the objects set forth above, and thosemade apparent from the foregoing description, are efficiently attainedand since certain changes may be made in the above construction withoutdeparting from the scope of the invention, it is intended that allmatters contained in the foregoing description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

[0176] It is also to be understood that the following claims areintended to cover all of the generic and specific features of theinvention herein described, and all statements of the scope of theinvention which, as a matter of language, might be said to falltherebetween.

What is claimed is:
 1. A laminated photocatalytic pulp papercharacterized in that a virgin pulp or a wastepaper pulp is laminated ona photocatalytic pulp composition in which 40-95 wt % of a pulp and/or apaper having the water content of 3 wt % or less, an average fiberdiameter of 5-300 μm and an average fiber length of 0.1-70 mm areblended with 5-60 wt % of titanium oxide.
 2. A laminated photocatalyticpulp paper characterized in that a virgin pulp or a wastepaper pulp islaminated on a photocatalytic pulp composition in which 5-60 wt % oftitanium oxide, 40-95 wt % of a pulp and/or a paper having the watercontent of 3 wt % or less, an average fiber diameter of 5-300 μm and anaverage fiber length of 0.1-70 mm, and 25-100 wt % relative to a totalweight of the titanium oxide, the pulp and/or the paper of athermoplastic resin are blended.
 3. A process for producing a laminatedphotocatalytic pulp paper, which comprises a step of imparting thestirring impact force to a blend obtained by blending 40-95 wt % of apulp and/or a paper which has been split and disaggregated to an averagefiber diameter of 5-300 μm and an average fiber length of 0.1-70 mm with5-60 wt % of titanium oxide to stir and, whereby, the shear exothermicheat is generated by a shearing force based on the stirring impact forceand the blend is dried by this shear exothermic heat to reduce the watercontent to 3 wt % or less, a step of swelling the pulp and/or the paperupon the drying to obtain a three-dimensionally entangled material, atreatment step of pushing the titanium oxide against the fiber surfaceof the pulp and/or the paper by the stirring impact force to fixthereto, and a step of laminating a virgin pulp or a wastepaper pulpafter the treatment step of pushing and fixing the titanium oxide.
 4. Aprocess for producing a laminated photocatalytic pulp paper, whichcomprises a step of imparting the stirring impact force to a blend inwhich 5-60 wt % of titanium oxide, 40-95 wt % of a pulp and/or a paperhaving the water content of 3 wt % or less, an average fiber diameter of5-300 μm and an average fiber length of 0.1-70 mm, and 25-100 wt %relative to a total weight of the titanium oxide, the pulp and/or thepaper of a thermoplastic resin are blended and, whereby, the shearexothermic heat is generated by a shearing force based on the stirringimpact force and the blend is dried by this shear exothermic heat toreduce the water content to 3 wt % or less, a step of swelling the pulpand/or the paper upon the drying to obtain a three-dimensionallyentangled material, a treatment step of pushing the titanium oxide andthe thermoplastic resin against the fiber surface of the pulp and/or thepaper by the stirring impact force to fix thereto, a step of pushingtitanium oxide against the fiber surface of the pulp and/or the paper tofix thereto, and a step of laminating a virgin pulp or a wastepaper pulpafter the treatment step of pushing and fixing the titanium oxide. 5.The process for preparing a laminated photocatalytic pulp paperaccording to claim 3, wherein a virgin pulp or a wastepaper pulp ispaper making-laminated in a paper making step after the treatment stepof pushing and fixing the titanium oxide.
 6. The laminatedphotocatalytic pulp paper according to claim 1, or the process forpreparing a laminated photocatalytic pulp paper according to claim 3,wherein the wastepaper pulp comprises a newspaper wastepaper via a DIPstep.
 7. The laminated photocatalytic pulp paper according to 1, whereinthe wastepaper pulp comprises a newspaper wastepaper and lamination isperformed using the wastepaper pulp as a core material or a substrate.8. The laminated photocatalytic pulp paper according to claim 1, whereina synthetic fiber having an average fiber length of 1-100 mm, an averagediameter of 10-40 μm and a melting point of 120° C. or higher is blendedwith 5-60 wt % of titanium oxide and 40-95 wt % of a pulp and/or apaper, at a maximum ratio of 1:9.
 9. The process for preparing alaminated photocatalytic pulp paper according to claim 3, wherein thepulp is a paperboard-like dry pulp and the dry pulp is used as a subjectto be treated and which further comprises a splitting and disaggregatingstep of imparting an impact grinding force to individual small sectionsto be treated formed by chopping the dry pulp into a plurality of smallsections to be treated, into ground and aggregated cotton-like fibrouspulp fibers having approximately the same length as that of a raw pulpand having no fuzz produced by the grinding.
 10. A splitting anddisaggregating apparatus for use in the process for preparing alaminated photocatalytic pulp paper as defined in claim 9, whichcomprises a fixed side impact grinding means in which a port forsupplying a plurality of chopped small sections to be treated is past inthe center of a fixed disc and respective fixing pins are successivelyprovided on a plurality of rotating loci, a mobile side impact grindingmeans in which a mobile disc is rotatably and drivably provided oppositeto the fixed and a plurality of mobile pins different from therespective fixing pins are successively provided on a rotating loci onthe mobile disc, and a take-out means for taking out fibrous smallsections to be treated which have been ground and aggregated intocotton-like fibers through an outlet.
 11. A paper string which comprisesa twisted laminated photocatalytic pulp paper, wherein said laminatedphotocatalytic pulp paper is obtained by laminating a virgin pulp or awastepaper pulp on a photocatalytic pulp composition in which 40-95 wt %of a pulp and/or a paper having the water content of 3 wt % or less, anaverage fiber diameter of 5-300 μm and an average fiber length of 0.1-70mm are blended with 5-60 wt % of titanium oxide, and cutting theresulting laminate to an arbitrary width.
 12. A process for preparingthe paper string comprising a photocatalytic paper as defined in claim11, which comprises cutting the aforementioned laminated photocatalyticpulp paper to a width of 5-50 mm, winding it in a roll-manner, andtwisting the roll.
 13. A molded article comprising the paper string asdefined in claim 1, which comprises a flat string, wherein said flatstring is obtained by stacking a plurality of paper strings on the sameplane.
 14. A molded article comprising the paper string as defined inclaim 1, which comprises a woven fabric comprising the paper string asdefined in claim 11 as a weft and a natural or chemical fiber as a warp.15. A molded article comprising the paper string as defined in claim 11,which comprises a combination of any two or three of the molded articlesas defined in claims
 11. 16. The process for preparing a laminatedphotocatalytic pulp paper according to claim 3, wherein the wastepaperpulp comprises a newspaper wastepaper and lamination is performed usingthe wastepaper pulp as a core material or a substrate.
 17. The processfor preparing a laminated photocatalytic pulp paper according to claim3, wherein a synthetic fiber having an average fiber length of 1-100 mm,an average diameter of 10-40 μm and a melting point of 120° C. or higheris blended with 5-60 wt % of titanium oxide and 40-95 wt % of a pulpand/or a paper, at a maximum ratio of 1:9.